Error: android/amd64 requires external (cgo) linking, but cgo is not enabled

[nicokosi]

Hello,

I cannot release nicokosi/gh-collab-scanner, cf. this GitHub Actions' job:

Run cli/gh-extension-precompile@v1
  with:
    go_version: 1.22
Run actions/setup-go@v3
Setup go version spec 1.22
Found in cache @ /opt/hostedtoolcache/go/1.22.0/x64
Added go to the path
Successfully set up Go version 1.22
go version go1.22.0 linux/amd64

go env
Run if [ -n "$INPUT_TOKEN" ]; then
Run if [ -n "$INPUT_TAG" ]; then
Run if [ -n "$INPUT_TITLE" ]; then
Run ${GITHUB_ACTION_PATH//\\//}/build_and_release.sh
go: downloading github.com/cli/go-gh/v2 v2.5.0
✂️...✂️
go: downloading github.com/mattn/go-runewidth v0.0.14
go: downloading github.com/rivo/uniseg v0.4.4
android/amd64 requires external (cgo) linking, but cgo is not enabled
Error: Process completed with exit code 1.

The last release that succeeded, v1.5.3:

• was using Go 1.20 instead of 1.22 ;
• had module github.com/cli/go-gh which has not been updated to v2 yet ;
• probably run on a previous version of the Ubuntu image.

I tried several changes: enable CGO (not sure it is correct), use a Windows runner etc. but I could not make the release succeed (see the GitHub Actions build history).

Do you have any advice/tip? Thank you!

[nicokosi]

No error after downgrading Go to 1.21, see gh-collab-scanner 1.5.4.
I presume that it is a Go issue related to GitHub Actions Runner Images, but maybe that this issue can be kept open (using Go 1.21 instead of latest 1.22 is a work-around)? 🤷

[Biswa96]

Try with CGO_ENABLED=1

[baruchiro]

With CGO_ENABLED=1:

gcc_android.c:6:10: fatal error: android/log.h: No such file or directory
    6 | #include <android/log.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.

Go version: 1.22

[the-hotmann]

Same error here. Since go v1.22 it requires cgo for at least those platforms:

• android/386
• android/amd64
• android/arm/v7
• ios/amd64
• ios/arm64

... maybe more

[andyfeller]

@nicokosi @Biswa96 @baruchiro @the-hotmann : firstly, thank you all for raising this issue and starting exploring the nuances. ❤

I'm currently looking into this issue to see how this changing behavior with Go 1.22 should be taken into account here 🙇

Research

Source: https://github.com/golang/go/blob/1ca31eac40c0400efc8211bc2483fd621264be11/src/internal/platform/supported.go#L83-L127

// MustLinkExternal reports whether goos/goarch requires external linking
// with or without cgo dependencies.
func MustLinkExternal(goos, goarch string, withCgo bool) bool {
	if withCgo {
		switch goarch {
		case "loong64", "mips", "mipsle", "mips64", "mips64le":
			// Internally linking cgo is incomplete on some architectures.
			// https://go.dev/issue/14449
			return true
		case "arm64":
			if goos == "windows" {
				// windows/arm64 internal linking is not implemented.
				return true
			}
		case "ppc64":
			// Big Endian PPC64 cgo internal linking is not implemented for aix or linux.
			// https://go.dev/issue/8912
			if goos == "aix" || goos == "linux" {
				return true
			}
		}

		switch goos {
		case "android":
			return true
		case "dragonfly":
			// It seems that on Dragonfly thread local storage is
			// set up by the dynamic linker, so internal cgo linking
			// doesn't work. Test case is "go test runtime/cgo".
			return true
		}
	}

	switch goos {
	case "android":
		if goarch != "arm64" {
			return true
		}
	case "ios":
		if goarch == "arm64" {
			return true
		}
	}
	return false
}

[andyfeller]

Update

Doing a bit of digging, one option I need to carve out a little more time to try comes from golang/go#42725 (comment), which highlights the need to override CC when compiling for android to point to Android NDK which is maintained on GitHub-hosted runners:

GOOS=android GOARCH=arm64 CGO_ENABLED=1 CC=$NDK_ROOT/21.3.6528147/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android30-clang go build

This should live within $ANDROID_NDK_HOME on GitHub-managed runners

Finding similar approaches in the wild

• https://github.com/tony114176876/Fclash/blob/e3b19ed66bdc35f8b7136a0cb653a4efd88cb56f/.github/workflows/package.yml#L215-L225

        - uses: nttld/setup-ndk@v1
          id: setup-ndk
          with:
            ndk-version: r25b
            add-to-path: true
        - name: Build Golang lib
          shell: bash
          env:
            ANDROID_NDK_HOME: ${{ steps.setup-ndk.outputs.ndk-path }}
          run: |
            pushd clash
            env GOOS=android GOARCH=arm64 CC=${ANDROID_NDK_HOME}/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android29-clang GOARM=7 CGO_ENABLED=1 go build -buildmode=c-shared -o ./libclash.so
            popd
            mkdir -p ./android/app/src/main/jniLibs/arm64-v8a
            ${ANDROID_NDK_HOME}/toolchains/llvm/prebuilt/linux-x86_64/bin/llvm-strip clash/libclash.so
            mv clash/libclash.so ./android/app/src/main/jniLibs/arm64-v8a/libclash.so

• https://github.com/poom/rclone/blob/49a6533bc1fdff3d3c32e4a2e7a81629af874abf/.github/workflows/build.yml#L310-L321

        - name: arm64-v8a Set environment variables
          shell: bash
          run: |
            echo "CC=$(echo $ANDROID_NDK/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android${RCLONE_NDK_VERSION}-clang)" >> $GITHUB_ENV
            echo "CC_FOR_TARGET=$CC" >> $GITHUB_ENV
            echo 'GOOS=android' >> $GITHUB_ENV
            echo 'GOARCH=arm64' >> $GITHUB_ENV
            echo 'CGO_ENABLED=1' >> $GITHUB_ENV
            echo 'CGO_LDFLAGS=-fuse-ld=lld -s -w' >> $GITHUB_ENV
  
        - name: arm64-v8a build
          run: go build -v -tags android -trimpath -ldflags '-s -X github.com/rclone/rclone/fs.Version='${VERSION} -o build/rclone-android-${RCLONE_NDK_VERSION}-armv8a .

• https://github.com/zllovesuki/t/blob/943ecd7237b6d2f676151c4173c0c4cfae4d634e/.github/workflows/build.yaml#L234-L238

        - name: Build android/arm64 Client w/ DNS Fix
          env:
            BUILD_VERSION: ${{ steps.get_version.outputs.VERSION }}
          run: |
            CC=$ANDROID_NDK_HOME/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android28-clang CXX=$ANDROID_NDK_HOME/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android28-clang++ CGO_ENABLED=1 GOARCH=arm64 GOOS=android go build -tags 'osusergo netgo' -ldflags "-X 'main.Version=$BUILD_VERSION' -s -w -extldflags -static" -a -o bin/t-client-android-arm64 ./cmd/client